Sanding disk attachment



Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to a sanding device and more particularly to improved means for attaching and securing a sanding disk to a revolvable plate of a sanding machine.

An object of the invention is the provision of a convenient and compact means for detachably connecting a disk adapted to carry a suitable sanding material to a driven supporting plate on a sanding machine.

A further object of the invention is the provision of a convenient means for detachably connecting a sanding disk to a revolvable supporting plate of a sanding machine so that the sanding disk is fiat over its entire surface area and presents an uninterrupted sanding surface.

Specifically, the invention comprises the utilization of a disk of sand paper or other similar material adapted to be positioned by means formed thereon, on a revolving supporting plate of a sanding machine, the attachment means comprising flat pocket like structures formed on the sanding disk itself and adapted to engage tongues formed on matching portions of the supporting plate so that the sanding disk may be detachably affixed thereto by simply positioning the sanding disk on the supporting plate and revolving it in relation thereto until the tongues have entered the pockets and secured it thereon. The pockets and tongues are so formed that the revolving motion of the sanding machine plate is imparted to the sanding disk thereby, and through abutting edges of the structure adjacent them, the revolving motion tending to force the tongues into the pockets at all times. Reversing the motion results in the disengagement of the sanding disk from the supporting plate, so that replacements can be readily made with a minimum of effort.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, can be made within the scope of what is claimed without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a cross sectional side elevation of a revolvable plate of a sanding machine; showing sand paper detachably afiixed thereto.

Figure 2 is a perspective view of the bottom side of the sanding machine plate shown in Figure 1.

Figure 3 is a perspective view of the back surface of a disk of sand paper or similar material adapted to be detachably aflixed to the plate shown in Figure 2.

Figure 4 is a fragmentary cross sectional view taken on lines 4-4 of Figure 1.

By referring to the drawing and Figure 1 in particular it will be seen that the invention comprises the formation of a simple and compact means of affixing asheet of sand paper H! or a sand paper supporting disk to a revolvable supporting plate H of a sanding machine, the abrasive surface of the sand paper being shown at 12. In order that the revolvable supporting plate can be mounted upon a revolving spindle l3 of a sanding machine, a supporting shank I4 is provided with a centrally positioned tapped opening l5 into which the revolving spindle I3 is threaded. An annular flange it formed on the supporting shank l4 carries a plurality of tapped openings I! adapted to threadably receive machine screws l8, the heads of which are countersunk in the revolvable supporting plate ll.

By referring to Figure 2 of the drawing wherein a perspective view of the bottom of the sanding plate is shown it will be seen that depending portions formed thereon provide a pair of oppositely disposed tongues [9 which are slightly elevated slidably engage a pair of matching pockets 23 as shown in Figure 3 of the drawing wherein a perspective view of the back surface of a piece of sand paper or similar material III is shown.

Still referring to Figure 3 it will be seen that the pockets 23 are formed by the placement of a spacer segment 24 between the pocket material 23 and the back of the sand paper l0 so as to provide space for the reception of the tongues l9, it is obvious that the pockets 23 could be formed in any other manner known to the art..

It has been determined that various types of sand paper or similar abrasive surfaced material may be formed into sanding disks and provided with pockets formed thereon as shown in Figure 3 of the drawing and that some forms of sand paper and similar material will require a stiffening which may be conveniently provided by the application of a coating of collodion or similar material to the back thereof thus suitably treating the sand paper disk so that it will be of sufficient rigidity and remain flat in relation to the work being sanded.

By referring again to Figure 2 of the drawing and to edges of the tongue carrying portion 2| afiixed to the plate II it will be seen that tapered sections terminating in knife edges 25 have been formed adjacent the tongues I!) so as to provide ease in removing the sanding disk in relation thereto. These tapered portions permit raised edges 26 as shown in Figure 3 on the back of the sand paper disk ID to slide over the same when the sanding disk I0 is removed by revolving it backwards in relation to the tongues 19 and pockets 23 at such times as replacements of the sanding disk are desirable. The tapers terminating in the knife edges 25 permit the speedy removal of the sanding disk.

It will thus be seen that a convenient and extremely compact means of detachably affixing a sand paper disk to a supporting plate of a sanding machine has been disclosed and that an alternate form is obvious wherein a disk of rigid material is substituted for the sanding disk It and formed in every manner similar to the sanding disk l0, including the pockets 2'3 thereon with the exception that it would not include an abrasive surface as this would be applied by gluing sections of sand paper to its outermost face or otherwise suitably affixing an abrasive surface thereon. The method of detachably affixing the sand paper disk or the sand paper carrying disk to the plate H would be exactly the same and the joint formed would be equally compact and simple in both instances.

It is obvious that the attachment means, to

be effective, must be directionally formed in agreement with the revolving direction of the supporting plate ll so that the tongues E9 of the revolving plate always tend to enter the pockets 23 when the sanding machine is in use thus continually providing a tight and compact joint. It will be seen that the driving force imparted the sanding disk ID by the supporting plate H is' distributed over considerable area on the sanding disk It! as the leading edges of the tongue carrying structure 2| engage the open edges of the pockets 23 across their complete length thus the driving force is applied completely across the sanding disk rather than at the relatively smaller area of the pockets themselves.

By referring to Figure l and to Figure 4 of the drawing it will be seen that an auxiliary means of insuring the engagement of the tongues [9 in the pockets 23 has been provided and comprises means for temporarily depressing the tongues I9 in relation to the plate ll so that the ends 22 of the tongues more readily engage the pockets 23. Said means comprises a manually operated L shaped lever 21 affixed to the upper surface of the plate II by means of a round head machine screw 28, the lever being preferably formed of spring steel so it normally remains elevated in relation to the upper surface of the plate II. A downwardly extending portion 29 of this L shaped lever is positioned within an opening 30 in the plate H so that the lower end of the downwardly extending portion 29 terminates adjacent the tongue I9. It is obvious that by manually depressing this L shaped lever it may be moved downwardly into engagement with the tongue I9 and suitably bend it so that it will more readily enter the pocket 23. The lever 21 is allowed to return to normal position as soon as the end 22 of the tongue l9 has entered the pocket 23 thus permitting the tongue to slide completely within the pocket.

What I claim is:

1. In combination with a sanding machine having "a revolvable spindle and supporting plate carried thereon and means for detachably connecting a sand paper disk thereto, said means comprising a pair of oppositely disposed pockets formed on the back of the said sand paper disk adapted to receive a pair of protruding tongues formed on and elevated slightly in relation to said revolvable supporting plate.

2. The combination of a sanding machine having a rotatable spindle and a rotatable supporta ing plate aflixed thereto, and a relatively flat supporting structure formed on the said supporting plate, tongues projecting therefrom slightly elevated in relation to the said plate and adapted to engage relatively flat pockets formed on the back of a disk of sand paper, said pockets of a size and shape adapted to receive the said tongues so that the said sand paper disk may be held in close relationship to the said plate so as to be effectively rotated thereby, the said pockets registering with the said supporting plate at points adjacent the said tongues, so as to form a flat backing structure for the said sandpaper disk.

3. Means for detachably connecting a sand paper disk to a rotatable supporting plate of a sanding machine, said means comprising a plurality of flat pockets formed on the back of the said sand paper disk and a plurality of fiat appropriately shaped tongues formed on and projecting from slightly raised portions of the said supporting plate so as to engage the said pockets when the said plate is rotated in relation to the sand paper disk, and L shaped levers positioned on the said plate and operatively engaging an opening in said plate so that an end of each L shaped lever is positioned adjacent one of the said tongues so that it may be depressed slightly thereby.

4. Means for detachably connecting a sand paper disk to a rotatable supporting plate of a sanding machine, said means comprising a plurality of flat pockets formed on the back of the said sand paper disk and raised portions formed on the said supporting plate adapted to be positioned adjacent the pockets on the sand paper disk when the supporting plate and sand paper disk are in close relationship, so as to form a fiat chine, said means comprising a plurality of flat pockets formed on the back of the said disk and raised portions formed on the said supporting plate adapted to be positioned adjacent the pockets on the disk when the supporting plate and disk are in close relationship, tongues formed on and projecting from the said raised portions of the supporting plate so as to engage the said pockets when the said plate is rotated in relation to the said disk, so as to form a fiat and compact joint therebetween, a face of the said disk adapted to have an abrasive material positioned thereon, and L shaped levers positioned on the said plate and operatively engaging an opening in said plate so that an end of each L shaped lever is positioned adjacent one of the said tongues so that it may be depressed slightly thereby.

WILLIAM E. GLTJOK. 

